OHAUS MB35 Advanced Infrared Moisture Analyzer

Overview

The OHAUS MB35 Advanced Infrared Moisture Analyzer is a precision benchtop instrument engineered for rapid, reliable quantification of moisture content in solid and semi-solid samples across pharmaceutical, food, chemical, and materials quality control laboratories. It operates on the principle of infrared halogen heating coupled with high-resolution analytical weighing—commonly referred to as thermogravimetric analysis (TGA) by loss on drying (LOD). A calibrated halogen lamp delivers uniform, controllable radiant heat across the sample surface, while a built-in analytical balance continuously monitors mass loss in real time. The integrated microprocessor calculates moisture percentage based on the initial and final dry mass, referenced to the original wet weight. Designed for compliance-critical environments, the MB35 supports method development, validation, and routine testing aligned with ASTM E1447, ISO 12879, USP <921>, and AOAC 952.03 methodologies.

Key Features

• High-precision dual-sensor system: 0.001 g readability combined with ±0.05% repeatability (for 10 g sample), ensuring metrological traceability per ISO/IEC 17025 requirements
• Programmable infrared heating: Adjustable temperature range from 50 °C to 160 °C in 5 °C increments, enabling optimization for thermally sensitive or refractory matrices
• Flexible endpoint detection: Dual-mode termination—user-defined timer (1–120 min, with 30-s resolution up to 60 min; 1-min resolution thereafter) or automatic moisture stabilization detection
• Intuitive backlit LCD display (128 × 64 pixel matrix): Simultaneously shows real-time % moisture, elapsed time, chamber temperature, and current mass
• Robust mechanical architecture: 9 cm diameter stainless-steel weighing pan, IP42-rated enclosure, and thermal shielding to minimize ambient drift
• Wide dynamic moisture range: Capable of accurate quantification from 0.05% to 100% moisture—suitable for hygroscopic powders, granules, polymers, botanicals, and dried foods

Sample Compatibility & Compliance

The MB35 accommodates heterogeneous, non-volatile, and moderately volatile samples—including tablets, resins, flour, coffee beans, activated carbon, and polymer pellets—provided volatiles other than water contribute negligibly to total mass loss. Sample size flexibility (3–10 g typical) allows statistical representation without overloading the pan. The instrument meets essential environmental operating conditions: 10–40 °C ambient temperature and ≤80% RH (non-condensing). Its design supports GLP/GMP workflows through user-accessible calibration logs, date/time-stamped result export, and configurable password protection for method editing. While not FDA 21 CFR Part 11–certified out-of-the-box, audit trails and electronic records can be enabled via optional OHAUS Connect software integration under validated IT infrastructure.

Software & Data Management

Data output is supported via RS232 serial interface (standard) for direct connection to PCs or LIMS. Optional OHAUS Connect software enables method storage (up to 99 protocols), automated report generation (PDF/CSV), statistical evaluation (mean, SD, RSD), and trend analysis across batches. All measurements include embedded metadata: operator ID, method name, start/end timestamps, ambient conditions (if external sensor connected), and calibration status flags. Exported files are compatible with Microsoft Excel and industry-standard QA/QC platforms. Firmware updates maintain alignment with evolving regulatory expectations—including enhanced data integrity safeguards introduced in v3.2+.

Applications

• Pharmaceutical QC: Verification of residual solvent levels in APIs, moisture content in excipients (e.g., lactose, microcrystalline cellulose), and stability-indicating assays per ICH Q1A(R2)
• Food manufacturing: Routine moisture verification in cereals, snacks, dairy powders, and pet food to ensure shelf-life compliance and prevent microbial proliferation
• Chemical production: Monitoring hydration state of catalysts, silica gels, and desiccants during synthesis and packaging
• Agricultural testing labs: Rapid assessment of grain moisture prior to storage or milling—supporting USDA FGIS and ISO 712 standards
• Academic research: Method development for novel biomaterials, hydrogels, and nanocomposites where gravimetric water uptake kinetics are critical

FAQ

What is the maximum sample weight capacity of the MB35?
The MB35 has a 35 g weighing capacity, optimized for typical LOD sample sizes between 3 g and 10 g.
Does the MB35 support multi-step heating programs?
No—the MB35 implements a single-stage, fixed-temperature heating profile. For multi-ramp protocols, consider the MB45 or Adventurer PRO series.
Can I validate my moisture method on this instrument?
Yes. The MB35 provides full access to raw mass-vs.-time datasets, repeatability testing tools, and calibration certificate documentation required for IQ/OQ/PQ execution.
Is the halogen lamp user-replaceable?
Yes. Lamp replacement is a field-serviceable procedure requiring only standard Torx tools and adherence to OHAUS Service Manual SM-MB35.
How often should I perform performance verification?
OHAUS recommends daily zero calibration and weekly verification using certified reference standards (e.g., sodium tartrate dihydrate for ~15.66% moisture), per ASTM E1447 Section 7.3.